The present invention relates to the field of digital image processing, and more specifically to distortion correction in digital images.
Digital cameras are used for still photography and videography and the captured digital images may be transferred to an image display device such as a monitor. Due to imperfections and natural limitations of cameras"" optical systems, the digital images displayed on a monitor may show geometrical distortions. Geometrical distortions are a class of optical aberrations that occur when the object is not situated on the optical axis of the camera""s lens system. Geometrical distortions depend on the angle that a ray incident on the lens makes with the optical axis. FIG. 1B illustrates a positive distortion (also called pincushion distortion) of the object illustrated in FIG. 1A, while FIG. 1C illustrates a negative distortion (also called barrel distortion) of the same object.
Geometrical distortions can be alleviated by equipping the camera with a more complicated, higher quality lens system. However, using a higher quality lens can substantially increase the camera""s weight, size, and cost.
Another method for compensating geometrical distortions in images is generating magnetic fields by positioning magnets or magnetic coils around the screen of an image display device.
Both solutions necessitate the physical and functional alteration of either the camera or the display device used to view the images.
A method and apparatus are disclosed for recreating an image free of geometrical distortion from a distorted image captured by a camera, wherein the distorted image is represented by a set of pixels in a camera grid. A distortion correction factor is determined such that, when applied to the camera grid, causes distortion in the distorted image to be substantially removed. Based on the distortion correction factor, a respective location in the camera grid is identified for each pixel in a display window. An intensity value to each pixel in the display window is assigned based on one or more pixels in the camera grid indicated by the location.
Additional features and benefits of the present invention will become apparent from the detailed description, figures, and claims set forth below.